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Biomedical subjects

J Bonelli

Publications and source records attributed to J Bonelli.

At least 55 records · Page 3Linked to original sources
PubMed1979

Hemodynamic characterization of bufuralol-HCl and pindolol based on the competitive effects of isoproterenol.

In this hemodynamic study a new beta-receptor blocker, Bufuralol-hydrochloride was compared with Pindolol under an Isoproterenol infusion with increasing doses in healthy male volunteers. We found the following results: 1. Before Isoproterenol peripheral resistance increased after acute i.v. application of Pindolol but decreased after Bufuralol-hydrochloride i.v. application. 2. After beta-receptor blockade with either Bufuralol-hydrochloride or with Pindolol a shift to the right of the dose effect relationship concerning heart rate and cardiac output under Isoproterenol infusion was observed, indicating beta 1-blockade. 3. The reduction of peripheral resistance which is usually observed as a sign of beta 2-blockade was also shifted to the right under the influence of both drugs. 4. This proves Bufuralol-hydrochloride to be a non-specific beta-blocking agent with an affinity to the beta 1- and beta 2-receptors. 5. Although Bufuralol-hydrochloride has a beta 2-blocking property which is even more pronounced than that of Pindolol, it reduces acutely, intravenously given, peripheral resistance.

Adrenergic beta-Antagonists↗
PubMed1979

[Lung function studies with the bronchodilator terbutaline].

The acute bronchodilator effect of the beta 2-adrenoceptor agonist terbutaline was tested single-blind cross-over in out-patients with chronic obstructive airways disease (intrinsic asthma). In 7 series comparisons were made with other marketed bronchodilators. Airways resistance was measured by whole body plethysmography. In another 3 series the effect on heart rate of terbutaline and other adrenoceptor agonists was tested in healthy volunteers. Terbutaline and the adrenoceptor agonists clenbuterol, epinephrine, fenoterol, hexoprenaline, isoprenaline, metaproterenol, reproterol and salbutamol, the vagolytics atropine, ipratropium bromide and AA 28-263, the xanthine-derivative theophylline ethylenediamine and one combined substance drug were used.

Adult↗
PubMed1978

[Haemodynamic characterization of a new beta-receptor blocker celiprolol (st1396) at rest and during ergometer exercise compared with propranolol (inderal) (author's transl)].

A new beta-receptor blocker (Celiprolol) was characterized in man by haemodynamic studies carried out on a random cross-over basis in 6 volunteers before and after intravenous administration of the drug or propranolol. The studies were performed at rest and in response to ergometer exercise. The studies showed that: 1. Celiprolol is a cardio-selective beta-receptor blocker with pronounced intrinsic sympathomimetic activity. Hence, Celiprolol increases the heart rate and cardiac output at rest. 2. The heart rate was reduced by Celiprolol during pronounced physical exercise. 3. Celiprolol probably has only a very slight blocking effect on those, beta1-receptors which mediate a positive inotropic effect. 4. The increase in blood pressure during exercise was less pronounced during Celiprolol medication than with propranolol.

Adrenergic beta-Antagonists↗
PubMed1978

Demonstration of two different types of beta1-receptors in man (selective blockade of the positively inotropic and the positively chronotropic effect of isoproterenol).

The hemodynamic effect of a beta-receptor blockade with mepindolol--a noncardioselective beta-receptor blocker--was studied in 6 male test subjects age 25 to 30 years with an increasing dose of isoproterenol. The cardiac output per min, the heart rate and the stroke volume, the wet blood pressure and the contractility parameters dp/dt max in the right and left ventricles were measured as part of the study. It was found that a dissociated right shift of the dose-effect curves occurred for the stroke volume, contractility parameters and heart rate. The following major conclusions can be made from an exact analysis of this result: 1. Evidence was produced that a distinction must be made in man with respect to the so-called beta1-receptors between those which mediate a specific effect on the heart rate and those which mediate a primarily positively inotropic effect. 2. There are apparently some beta-receptor blockers which inhibit the frequency receptors primarily and the inotropic receptors to a lesser extent. 3. Through their beta 2-effect, noncardioselective beta-receptor blockers can partly compensate for their negatively inotropic effect on the heart by maintaining the Frank Starling mechanism.

Adult↗
PubMed1978

Decrease of peripheral resistance after acute intravenous application of a new beta-receptor blocking agents, bufuralol HCl.

The hemodynamic effects of a new beta-receptor blocking agent, bufuraolo HCl, were compared with those of pindolol. Contrary to pindolol, bufuralol HCl induces a decrease of the peripheral resistance immediately. Under exercise conditions, the peripheral resistance increases under pindolol whereas it remains constant under bufuralol HCl in spite of reduced cardiac output. As an explanation, an effect of bufuralol HCl on peripheral resistance is discussed which might be independent of the beta-receptor blocking effects in the periphery.

Adrenergic beta-Antagonists↗
PubMed1978

[Hemodynamics in patients with coronary heart disease under conditions of physical exercise before and after mepindolol-sulfate (author's transl)].

UNLABELLED: The effect of exercise upon hemodynamic variables was investigated in seven patients with coronary artery disease during an eight-week double blind cross-over study with placebo and with mepindolol-sulfate, a new beta-receptor blocking agent. RESULTS: 1. The first hemodynamic sign of myocardial ischemia during exercise was an increase of pulmonary capillary pressure in parallel with ST-segment depression in the Ecg. 2. Angina was accompanied by a fall of the stroke volume and an increase of the peripheral resistance. 3. During beta-receptor blockade with mepindolol-sulfate angina was compensated, the unfavourable hemodynamic effects seen during placebo did not occur. 4. No signs of congestive heart failure were found during mepindolol-sulfate-therapy. 5. Mepindolol-sulfate showed a pronounced blood-pressure lowering effect.

Aged↗
PubMed1978

[Hemodynamic differences in the effects of mepindolol-sulfate and propranolol after 4 weeks treatment under conditions of rest and physical exercise in patients with coronary heart disease (author's transl)].

UNLABELLED: The hemodynamic effect of mepindolol-sulfate, a new non-cardioselective beta-receptor blocking agent, was compared with the hemodynamic effect of propranolol at rest and during exercise in five patients with coronary artery disease during an eight week double blind cross-over study. RESULTS: 1. The beta-receptor blocking effect of mepindolol-sulfate is 25 times higher than that of propranolol. 2. No hemodynamic difference between mepindolol-sulfate and propranolol was seen at rest. 3. The increase of blood pressure during exercise was less pronounced during mepindolol-sulfate-medication compared to propranolol. 4. Propranolol seems to achieve a more pronounced negative inotropic effect than mepindolol-sulfate.

Aged↗
PubMed1978

The pharmacokinetics of digoxin in patients with manifest hyperthyroidism and after normalization of thyroid function.

The pharmakokinetic data (elimination half-life, apparent distribution volume, total and renal clearance and cumulative urine excretion) were determined after intravenous administration of 1 mg digoxin in 9 female patients with an average age of 52 +/- 15 years with manifest hyperthyroidism. The study protocol was repeated after normalization of thyroid function by means of conventional thyrostatic therapy. Digoxin was determined by radioimmunoassay.

Aged↗
PubMed1977

Effect of exercise and of prolonged oral administration of propranolol on haemodynamic variables, plasma renin concentration, plasma aldosterone and c-AMP.

The effect of submaximal exercise upon haemodynamic and biochemical variables was investigated in healthy male subjects, aged 17-27 years, before and at the end of 2 weeks treatment with propranolol (40 mg p.o., q.i.d.). Propranolol reduced the resting blood pressure in normal subjects significantly. This effect was due to reduction of cardiac output and of systemic vascular resistance. No effect of propranolol on BP was seen during maximal exercise, since a reduced cardiac output was accompanied by an increased peripheral resistance. The reduction of cardiac output during exercise can be compensated in part by an increase in stroke volume. The sympathetic activity induced by physical exercise in normotensives increased plasma renin concentration (PRC) and plasma aldosterone (PA), and suppressed urinary excretion of c-AMP. PRC returned to basal levels after 45 min. No increase of PRC was observed after exercise in subjects treated with propranolol. Yet the increase of PA was not completely suppressed. No direct relation was demonstrated between PRC and the haemodynamic variables before or during the administration of propranolol.

Administration, Oral↗
PubMed1977

Contribution to the biochemical characterization of cardiac glycosides concerning their influence on ATP-ases.

1. A comparison of the complex binding constants of different glycosides show no significant differences between these different glycosides at least not in the model containing ATP. 2. There are greater differences regarding the ATP-ase activity of the different glycoside complexes measured by means of the Rb-transport method. 3. The absorption of different proscillaridin and methylproscillaridin preparations was investigated with this method. 4. Using the rat as experimental animal the effect of different glycosides on the Na-K and Ca ATP-ase of the heart muscle was demonstrated showing a remarkable activation of the Ca-activated ATP-ase caused by proscillaridin. In order to find an explanation for the therapeutic and toxic effects these investigations have to be repeated in the pig, which shows more similarities in the ATP-ase distribution to man than the rat.

Adenosine Triphosphatases↗
PubMed1977

A model for distinguishing between beta1-receptors which mediate a specific effect on the heart rate and those which mediate a positively inotropic effect.

The study was conducted in six healthy male volunteers aged between 20 and 30 years. Cardiac output was determined by means of the Swan-Ganz-thermodilution-method. A control-study was carried out, during which an isoproterenolinfusion with increasing doses was given. Fifty minutes after i.v. injection of a beta-receptor-blocker the hemodynamic parameters were measured again under increasing doses of isoproterenol until the block was overcome. This study procedure was performed twice in each subject at an interval of at least 14 days. For the one study 15 mg propranolol i.v. and for the other 0,5 mg mepindolol i.v., a new beta-receptor-blocker, were injected. After i.v. injection of propranolol the dose-response-relationship-curve for the heart-rate (HR) and stroke volume (SV) describes a definite shift to the right. After mepindolol the dose-effect curve for the heart rate describes a definite shift to the right, as seen with propranolol. In contrast, only a very slight shift can be seen in respect of the SV increase, i.e. the SV and HR curves dissociate under mepindolol. The results of our study indicate, that a distinction can be made with respect to the so-called beta 1-receptors between those mediating a specific effect on the heart-rate and those mediating a mainly positive inotropic effect.

Adrenergic beta-Antagonists↗
PubMed1977

The bio-availability of beta-acetyldigoxine (Novodigal) alone and combined with oxyfedrine (Ildamen-Novodigal).

The bio-availability of various galenic preparations of beta-acetyldigoxine was tested in six healthy probands after a single oral dose (1 mg). The availability parameters were calculated from the areas under the plasma concentration curves and from the cumulative urinal excretion. There was no significant difference between the bio-availabilities of Novodigal (beta-acetyledigoxine tablets), Ildamen-Novodigal (beta-acetyldigoxine and oxyfedrine) and an alcoholic solution of beta-acetyldigoxine. Correlation calculations showed that the determination of the plasma concentration courses up to six hours after substance application are most favourite in regard to judging the absorption processes of digoxine preparations. For the assessment of the bio-availability, the methods of comparing the areas under the blood level curves of 0 to 6 hrs and of comparing the cumulative urinal excretion over a period of 24 hrs were of equal validity.

Adult↗
PubMed1977

Pharmacokinetics of Lidaprim in cases of impaired renal function.

Elimination half-life times, plasma concentrations, and minimal cumulation factors are being determined resp. calculated for trimethoprime and sulfametrole (free as well as total amounts)--both combination partners of Lidaprim--in healthy volunteers and in patients with impaired renal function. There is a strong influence of renal function on the cumulation of the metabolized part of the sulfonamide, a weaker one on trimethoprime, and almost none on the free sulfonamide. On account of the sulfonamide metabolite cumulation, a reduction by half of the standard dose of Lidaprim is recommended if the creatinine clearance is below 20-30 ml/min.

Adult↗